//题目：请输入星期几的第一个字母来判断一下是星期几，如果第一个字母一样，则继续判断第二个字母。
#include<stdio.h>
void main()
{
    char letter;
    printf("Please input the first letter of somday.\n");
    while((letter=getchar())!='Y')
    {
        switch(letter)
    {
    case 'S':printf("please input second letter\n");
            if((letter=getchar())=='a')
            printf("saturday\n");
            else if ((letter=getchar())=='u')
                printf("sunday\n");
                else printf("data error\n");
                break;
    case'F':printf("friday\n");break;
    case'M':printf("monday\n");break;
    case'T':printf("please input second letter\n");
            if((letter=getchar())=='u')
                printf("tuesday\n");
            else if((letter=getchar())=='h')
                printf("thursday\n");
            else printf("data error\n");
                break;
    case'W':printf("wednesday\n");break;
    }
    
    }
}